Every year, the 62-year-old Somerville resident throws a massive Memorial Day party. Dozens — maybe hundreds — will gather on his lawn next Monday: family, friends, business associates, local politicians.

Even complete strangers are welcome to grab some grub for free.

“It doesn’t matter,” Reitman explained. “That’s what the day is for.”

And in Reitman’s Somerset County town, Memorial Day is more than a holiday. It’s also the date of the Tour of Somerville.

Some call it the Kentucky Derby of cycling. Record books call it the oldest continuous bike race in the country. In Somerville, residents call it the biggest bash of the year — one that often draws more than 20,000 spectators to the borough’s bustling downtown.

This year’s is the 67th annual, a four-day event that starts Friday and ends Monday with the premier, 50-mile race. Many sit in lawn chairs or stand on rooftops along Main Street, watching professional racers whiz by. Vendors dot sidewalks, selling hot dogs and Italian ice.

Amanda Brown/The Star-LedgerCyclists compete in last year's Tour of Somerville.

“It’s a bicycle race that happens to wrap itself around an ongoing street festival, family gatherings and thousands of people,” said Ron Czajkowski, a 61-year-old borough resident who has been to every race since 1956.

“It’s the kickoff of summer for Somerville,” Mayor Brian Gallagher added. “People come out of the hibernation of winter.”

High Street becomes a series of lawn parties swarming with people.

“I know bike riders who have taken a long time to get back to the podium because they stopped at parties,” said Joe Saling, who has raced in numerous Tours and has long been the race’s announcer. “People give them a few cold ones.”

Reitman’s has become the most iconic lawn celebration. The Somerville native fell in love with the race as a kid. In 1994, he bought the two-story converted home that houses his public relations firm partly, he said, to throw a party to coincide with the Tour.

He spends up to $600 each year on the bash. This year, he even has a high-school buddy flying in from San Diego to attend.

“People come back to town for Thanksgiving and Memorial Day,” Reitman said. “You know you’re going to see people you haven’t seen in a while.”

The first tour was 1940, organized by local bike shop owner Fred “Pop” Kugler. It’s become so prestigious that Lance Armstrong, the Babe Ruth of the sport, mentioned the event in a recent interview. Greg LeMond rode the course before he became the first American to win the Tour de France in 1986 — though he didn’t win in Somerville.

It also has an international appeal. Of the last four winners, two were from Argentina and another from Australia. This year, riders from New Zealand, Canada and Mexico are expected. At least 750 cyclists will ride, said Daniel Puntillo, executive director of Middle Earth, the Bridgewater-based youth-assistance group that has organized the race for nearly a decade.

The event starts Friday with Manville Madness, a 20-mile race around neighboring Manville. On Saturday is the Frank “Nap” Torpy Memorial Hills race, a 77-miler that stretches across 13 towns. On Sunday, Bound Brook will host four races.

Memorial Day will start with a parade at 9 a.m., followed by six races — including ones for juniors, people 50 years or older and women. The main professional race is 50 miles around a 1.25-mile course than runs throughout downtown Somerville. The purse is $15,000.

The Tour used to draw 30,000 spectators. But those numbers have dropped, organizers said, with bigger races popping up around the nation and malls and modern technology diverting people’s attention.

This will also be the first Tour since the U.S. Bicycling Hall of Fame left Somerville for California. But organizers say they have been gradually pushing the Tour toward becoming more of a community event. There are pony rides, petting zoos, spin art, basketball tournaments and live music.

“It’s a slice of Americana,” Czajkowski said of the Tour. “It’s a happening.”

David Gard/For The Star-LedgerRichard Reitman outside his High Street office in Somerville.